Near-Infrared Spectroscopy Reveals Brain Hypoxia and Cerebrovascular Dysregulation in Primary Biliary Cholangitis

Brain hypoxia, neurocognitive impairment, and quality of life in people post-COVID-19

OBJECTIVE

Systemic hypoxia occurs in COVID-19 infection; however, it is unknown if cerebral hypoxia occurs in convalescent individuals. We have evidence from other conditions associated with central nervous system inflammation that hypoxia may occur in the brain. If so, hypoxia could reduce the quality of life and brain function. This study was undertaken to assess if brain hypoxia occurs in individuals after recovery from acute COVID-19 infection and if this hypoxia is associated with neurocognitive impairment and reduced quality of life.

METHODS

Using frequency-domain near-infrared spectroscopy (fdNIRS), we measured cerebral tissue oxygen saturation (StO2) (a measure of hypoxia) in participants who had contracted COVID-19 at least 8 weeks prior to the study visit and healthy controls. We also conducted neuropsychological assessments and health-related quality of life assessments, fatigue, and depression.

RESULTS

Fifty-six percent of the post-COVID-19 participants self-reported having persistent symptoms (from a list of 18), with the most reported symptom being fatigue and brain fog. There was a gradation in the decrease of oxyhemoglobin between controls, and normoxic and hypoxic post-COVID-19 groups (31.7 ± 8.3 μM, 27.8 ± 7.0 μM and 21.1 ± 7.2 μM, respectively, p = 0.028, p = 0.005, and p = 0.081). We detected that 24% of convalescent individuals' post-COVID-19 infection had reduced StO2 in the brain and that this relates to reduced neurological function and quality of life.

INTERPRETATION

We believe that the hypoxia reported here will have health consequences for these individuals, and this is reflected in the correlation of hypoxia with greater symptomology. With the fdNIRS technology, combined with neuropsychological assessment, we may be able to identify individuals at risk of hypoxia-related symptomology and target individuals that are likely to respond to treatments aimed at improving cerebral oxygenation.

Regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract and MRI research progress: a literature review

Patients with liver disease are prone to various cognitive impairments. It is undeniable that cognitive impairment is often regulated by both the nervous system and the immune system. In this review our research focused on the regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract, and revealed that its mechanisms may be involved with hyperammonemia, neuroinflammation, brain energy and neurotransmitter metabolic disorders, and liver-derived factors. In addition, we share the emerging research progress in magnetic resonance imaging techniques of the brain during mild cognitive impairment associated with liver disease, in order to provide ideas for the prevention and treatment of mild cognitive impairment in liver disease.

Hematologic traits and primary biliary cholangitis: a Mendelian randomization study

Hematologic abnormalities was observationally associated with the susceptibility of primary biliary cholangitis (PBC). However, the conclusion is still controversial and whether there exists a causal association remains elusive. Here we aimed to explore the causative role of hematological traits in the risk of PBC. We conducted two-sample and multivariable Mendelian randomization analyses based on summary statistics from previous large genome-wide association studies. Totally twelve red blood cell and six white blood cell traits were analyzed. Genetically determined higher hemoglobin level was significantly associated with a reduced risk of PBC (OR: 0.62, 95% CI: 0.47-0.81, P: 5.59E-04). Meanwhile, higher hematocrit level was nominally associated with reduced risk of PBC (OR: 0.73, 95% CI: 0.57-0.93, P: 0.01). These results could help better understand the role of hematological traits in the risk of PBC, and provide potential targets for the disease prevention and treatment.

Synthesis of ursodeoxycholic acid by electrochemical stereoselective reduction of 7-ketolithocholic acid in aprotic solvents

A novel method of producing ursodeoxycholic acid was developed through electrochemical stereoselective reduction of 7-ketolithocholic acid (7K-LCA) in a undivided electrolytic cell and aprotic solvents as electrolyte. Five aprotic solvents were investigated as electrolytes, the simple structure of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) were easily attacked by chloride ions and undergo nucleophilic reactions, resulting in no target reactions. The structure of hexamethylphosphoric triamide (HMPA) and 1,3-methyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU) is relatively complex, but chloride ions can still attack them, and it was easier for 7K-LCA to directly undergo a reduction reaction under the action of electric current, because of the small steric hindrance of chenodeoxycholic acid (CDCA), 7K-LCA was stereoselectively reduced to CDCA. Due to the stable structure of the five-membered imidazole ring of 1,3-dimethyl-2-imidazolidinone (DMI), 7K-LCA undergoes two nucleophilic and a "Walden inversion", thereby stereoselective reduction of 7K-LCA to UDCA. In DMI, the highest conversion rate of 7K-LCA was 58.3%, the yield of UDCA was 34.9%, ee value was 100%. Linear sweep voltammetry was used to explore the electrochemical behavior of the reaction, and the electrolysis results were consistent with the linear sweep voltammetry. The product was characterized by using IR, ¹H NMR and ¹³C NMR, it confirm the product was UDCA. The method developed in this paper provides a relatively environmentally friendly and low-consumption method for large-scale production of ursodeoxycholic acid, and provides a valuable reference for the asymmetric electrochemical reduction of ketone groups.

Managing cognitive symptoms and fatigue in cholestatic liver disease

Introduction: Patients with cholestatic diseases may develop fatigue and cognitive symptoms. The impact of symptom burden may be significant in some patients. To date, there are no effective pharmacological therapies to improve cognitive symptoms or fatigue in cholestasis and we are wholly reliant on supportive approaches. Area covered: This review provides an overview of cognitive symptoms and fatigue in the cholestatic liver disease primary biliary cholangitis (PBC), including pathophysiology and our approach to the management of these symptoms. Expert opinion: The impact of fatigue and cognitive symptoms on the perceived quality of life can be profound for patients with PBC. The pathophysiology of these symptoms is complex and poorly understood, making the development of therapeutic trials of symptom-directed therapies challenging. The current recommended management for fatigue and cognitive symptoms is mainly supportive.

Synthesis and evaluation of new dinitrobenzamide mustards in human prostate cancer

Tumor hypoxia has been widely explored over the years as a diagnostic and therapeutic marker. Herein, we have reported the design and synthesis of a series of dinitrobenzamide mustards (DNBM) based on the PR-104A hypoxia-selective prodrug. Specifically, we explored the impact of various leaving groups and the introduction of a carboxylic acid group on the biological performance of the DNBM constructs. Once in hand, the Log D values, cytotoxicity in PC-3 and DU-145 human prostate cancer cells lines and the hypoxia selectivities of the DNBM analogs were examined. Overall, the DNBM constructs were found to be tolerant to modifications with none of the explored modifications substantially degrading the cytotoxic potential of the constructs.